A handheld diabetes manager is presented with an improved graphical user interface for a bolus calculator. The bolus calculator is configured to receive blood glucose measurements from a blood glucose measurement module and operates, in response to an input, to compute an insulin recommendation for a patient based in part on the blood glucose measurements. The graphical user interface for the bolus calculator includes a health adjustment screen that enables a user to input a value for health events associated with the insulin recommendation, where the input value represents a cumulative effect of the health events on insulin of the patient and the health adjustment screen presents a different icon for each of the health events associated with the insulin recommendation.